Conventionally, a form-fill-seal machine having an ultrasonic sealing device, such as that disclosed in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2001-233309), is used as a form-fill-seal machine for shaping a bag from a film-shaped packaging material and filling the bag with packaged contents such as a snack food or the like. After applying fine ultrasonic oscillation to the thermoplastic packaging material and melting the material, the ultrasonic sealing device applies pressure to and seals the packaging material.